An acrylic aquarium is said to be 17 times tougher then a glass one. Also, I remember reading about how much the temperture doesnt fluctuate as much when having an acrylic tank. Crowning lightest of about 50% more then glass.

Im not sure which one to pick for the 30 gallon im thinking of getting...but if you want to go with glass just get a good, solid stand.

As long as your not banging your tank with a plastic hammer daily, I'm sure the glass wont break. I have a very good glass 2.5 tank, and I had a VERY THIN glass 2 gal bowl and I have another 3 gal bowl with VERY THIN GLASS. I've had all these tanks for over 3 months, And I do not have a single chip or scratch. I prefer glass because it doesnt scratch, and what would you be doing to break a glass tank? Becuase if you hit a glass tank with a hammer or something, it WILL break. But so will an acrilic. Also, you really should have made this a poll =P